Audi A2 - Misfire on Audi A2

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Wed 18 Nov 2015 20:20
Audi A2 - Misfire on Audi A2 - John Scott

Update on previous narrative.On running car at high revs the car does not misfire.Lower the revs to tickover and the engine warning light comes on and the car misfires.Anyone any ideas??

Reply | Report as offensive | Link
Wed 18 Nov 2015 21:01
Audi A2 - Misfire on Audi A2 - Sjd148905
Hi there,

I would check the spark plugs - this engine seems to suffer from a leaking cam cover where the spark plugs are and you may find a 'well' of oil down the middle pair (check both 2 and 3). In the short term simply cleaning this out with absorbent tissue should help, which is where I am with a 108K mile 2001 car. I haven't fixed the problem yet, but have to clean it up every 2 months.
Reply | Report as offensive | Link
Wed 18 Nov 2015 22:03
Audi A2 - Misfire on Audi A2 - elekie&a/c doctor
What was the result of the cylinder compression test and which cylinder does the ecu show as misfiring?
Reply | Report as offensive | Link
Fri 20 Nov 2015 13:07
Audi A2 - Misfire on Audi A2 - John Scott

Thanks for your response.Cylinder pressures within normal levels.

Reply | Report as offensive | Link
Wed 18 Nov 2015 23:16
Audi A2 - Misfire on Audi A2 - Big John

Why two threads?

In previous thread plugs/leads have already been changed etc..

If not the coil pack(Floor the throttle at standstill - if it suddenly sounds like a 2cv it's coil pack - change anyway - it's cheap! ) then compression test important. Lack of compression causes misfire at lower revs but better at higher revs.

On compression test if a cylinder is very low, - squirt a bit of oil in plu hole-

If compression shoots up it's bores/rings (will always raise a bit) if not it's valves/head gasket

Worrylingly if it's just a "single" cylinder failure I suspect a compression/engine issue - If it's two cylinders likely to be coil pack (could be head as well).

Edited by Big John on 18/11/2015 at 23:31

Reply | Report as offensive | Link
Fri 20 Nov 2015 14:17
Audi A2 - Misfire on Audi A2 - Railroad.

Engine misfires at idle, but not when the throttle is open? I'd suspect an intake vacuum leak.

Reply | Report as offensive | Link
Fri 20 Nov 2015 19:50
Audi A2 - Misfire on Audi A2 - Big John

The problem is on this engine injectors are nearish to the valves so there is not much to leak (that would cause a misfire)

Could be injector of course ( & the seating of) , but I would still start with a compression test and still change the wasted spark coil pack that is a known weak spot of this engine

Reply | Report as offensive | Link

Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.

The Good Garage Guide